increased preflight instruction fee padding to 3 million (#1127)

cmd/soroban-rpc/internal/test/simulate_transaction_test.go

@@ -236,15 +236,19 @@ func TestSimulateTransactionSucceeds(t *testing.T) {
 			ReadBytes:    0,
 			WriteBytes:   7048,
 		},
-		ResourceFee: 113910,
+		// the resulting fee is derived from the compute factors and a default padding is applied to instructions by preflight
+		// for test purposes, the most deterministic way to assert the resulting fee is expected value in test scope, is to capture
+		// the resulting fee from current preflight output and re-plug it in here, rather than try to re-implement the cost-model algo
+		// in the test.
+		ResourceFee: 135910,
 	}
 
 	// First, decode and compare the transaction data so we get a decent diff if it fails.
 	var transactionData xdr.SorobanTransactionData
 	err := xdr.SafeUnmarshalBase64(result.TransactionData, &transactionData)
 	assert.NoError(t, err)
 	assert.Equal(t, expectedTransactionData.Resources.Footprint, transactionData.Resources.Footprint)
-	assert.InDelta(t, uint32(expectedTransactionData.Resources.Instructions), uint32(transactionData.Resources.Instructions), 200000)
+	assert.InDelta(t, uint32(expectedTransactionData.Resources.Instructions), uint32(transactionData.Resources.Instructions), 3200000)
 	assert.InDelta(t, uint32(expectedTransactionData.Resources.ReadBytes), uint32(transactionData.Resources.ReadBytes), 10)
 	assert.InDelta(t, uint32(expectedTransactionData.Resources.WriteBytes), uint32(transactionData.Resources.WriteBytes), 300)
 	assert.InDelta(t, int64(expectedTransactionData.ResourceFee), int64(transactionData.ResourceFee), 3000)
@@ -1122,7 +1126,11 @@ func TestSimulateSystemEvent(t *testing.T) {
 	require.NoError(t, err)
 
 	assert.InDelta(t, 7464, uint32(transactionData.Resources.ReadBytes), 200)
-	assert.InDelta(t, 80980, int64(transactionData.ResourceFee), 5000)
+	// the resulting fee is derived from compute factors and a default padding is applied to instructions by preflight
+	// for test purposes, the most deterministic way to assert the resulting fee is expected value in test scope, is to capture
+	// the resulting fee from current preflight output and re-plug it in here, rather than try to re-implement the cost-model algo
+	// in the test.
+	assert.InDelta(t, 100980, int64(transactionData.ResourceFee), 5000)
 	assert.InDelta(t, 104, uint32(transactionData.Resources.WriteBytes), 15)
 	require.GreaterOrEqual(t, len(response.Events), 3)
 }

cmd/soroban-rpc/lib/preflight/src/fees.rs

@@ -138,12 +138,12 @@ fn calculate_host_function_soroban_resources(
         .map(|c| c.encoded_new_value.as_ref().map_or(0, Vec::len) as u32)
         .sum();
 
-    // Add a 20% leeway with a minimum of 1 million instructions
+    // Add a 20% leeway with a minimum of 3 million instructions
     let budget_instructions = budget
         .get_cpu_insns_consumed()
         .context("cannot get instructions consumed")?;
     let instructions = max(
-        budget_instructions + 1000000,
+        budget_instructions + 3000000,
         budget_instructions * 120 / 100,
     );
     Ok(SorobanResources {